I have a PDF book (it's not a scanned book) with size of 4.67 * 7.52 inches. The text sits in the middle of Foxit PDF reader in my laptop by default which I can enlarge to full page view without any problem.

I have converted it to epub and PDF using Calibre 0.7.57 with output text to "Sony Reader" But when I open it in the Reader, the text is too small and half the page is blank and the text goes in the upper right hand corner and again
lower left hand corner of the screen. Is there any way to fix this?

I think if I can define the text and font size in Calibre and then convert, it should be perfect but I am not sure how to do this and whether this or any other method will help.